1. Field of the Invention
The invention relates to a pattern forming method, an actinic ray-sensitive or radiation-sensitive resin composition, a resist film, a method for manufacturing an electronic device, and an electronic device, each of which is suitably used in a process for manufacturing semiconductors such as ICs, a process for manufacturing liquid crystals or circuit boards such as a thermal head, and lithographic processes in photo-fabrication in addition to these. In particular, the invention relates to a pattern forming method favorably used in exposure with a KrF exposure apparatus, an actinic ray-sensitive or radiation-sensitive resin composition, a resist film, a method for manufacturing an electronic device, and an electronic device.
2. Description of the Related Art
Since the development of a resist for use with a KrF excimer laser (248 nm), an image forming method known as chemical amplification has been used as an image forming method of a resist in order to compensate for sensitivity deterioration caused by light absorption. As an example, description will be given of a positive type chemical amplification image forming method, which is an image forming method in which, by exposure such as an excimer laser, electron beams, extreme ultraviolet light, or the like, an acid generator is decomposed at exposed portions to generate an acid, the generated acid is used as a reaction catalyst in a post exposure bake (PEB: Post Exposure Bake) to convert an alkali-insoluble group into an alkali-soluble group, and the exposed portions are removed using an alkali developer.
In the above-described method, various alkali developers have been proposed; however, an aqueous alkali developer having 2.38%-by-mass TMAH (tetramethylammonium hydroxide aqueous solution) is generally used. In patterning in which developing is performed with the above-described alkali developer, there is a problem of development defects generated after development since the peeling property of the film formed from the resist composition is poor.
As patterning in which developing is performed with the above-described alkali developer, for example, for the purpose of improving the sensitivity, high solubility contrast, pattern profile, and line edge roughness, and reducing standing waves and development defects, there is known a resist composition containing an anthracene compound (refer to JP2011-113065A).
On the other hand, as uses of the above-described resist technique, microfabrication applications such as ion implantation applications using the resist composition in ion implanting (charge injection) which is one step during the creation of a logic device or the like are continuing to be developed.
In a case where the resist composition is used as an ion implantation application, the resist composition may be coated, exposed, and developed on a substrate patterned in advance, and there is a demand for fine processing on an uneven substrate.
However, according to the influence of standing waves due to reflection of the exposure light from the substrate and the diffuse reflection of the exposure light due to an uneven portion in the above-described uneven substrate, the shape of the obtained pattern may be adversely affected.
In addition, a method providing an antireflection film (Bottom Anti-Reflective Coating: BARC) between the resist film and the substrate is known; however, if an antireflection film is provided, in particular, in a case where the resist composition is used as an ion implantation application, a step of removing the antireflection film by etching before the ion implantation is necessary, and the manufacturing costs are increased.
In addition, from the demand from the above-described fine processing technique, development is also being carried out on fine pattern forming using a negative image, as well as the current mainstream positive type, (for example, refer to JP2010-40849A, JP2008-292975A, and JP2010-217884A). This is because, in the manufacturing of semiconductor elements or the like, while there is a demand for forming a pattern having various shapes such as lines, trenches (grooves), and holes, there are patterns of trenches, holes, and the like which are difficult to form using the current positive type resist.
However, in the negative type pattern forming method according to such organic solvent development, there are problems in that the pattern easily takes on an undercut shape. In addition, there is room for improvement in the roughness property such as the line width roughness (Line Width Roughness: LWR), the exposure latitude (EL), and the reduction of developer defects.